As is well known in the art, an internal combustion engine is a machine for converting heat energy into mechanical work. In an internal combustion engine, a fuel-air mixture that has been introduced into a combustion chamber is compressed as a piston slides within the chamber. A high voltage for ignition is applied to a spark plug installed in the combustion chamber to generate an electric spark to ignite the fuel-air mixture. The resulting combustion pushes the piston downwardly within the chamber, thereby producing a force that is convertible to a rotary output through the use of a crankshaft.
The crankshaft of the engine rotates at a high rate. Due to uneven forces acting upon the crankshaft, the crankshaft often vibrates when rotated. To counteract the uneven forces acting upon the crankshaft, counterweights are often rigidly coupled to, or as more often the case, formed integrally with the crankshaft, to balance the uneven forces acting upon the crankshaft, thereby eliminating/reducing vibrations in the crankshaft.
Although somewhat effective, previously developed crankshaft balancing techniques as described above are not effective in balancing crankshafts which both rotate and orbit so as to have two axes of rotation. Rigidly attaching counterweights directly to a crankshaft which both rotates and orbits would only effectively balance the crankshaft's rotation about its own axis, and would result in increased unbalancing forces during the crankshaft's orbital movement. Thus, there exists a need for a power transfer assembly having a crankshaft which is balanced while both rotating and orbiting.
Further, crankshafts which both rotate and orbit having additional problems. The movement of the crankshaft in both a rotational and orbital manner tends to magnify misalignment issues of the rotating components of the engine. Therefore, there exits a need for a power transfer assembly capable of mitigating or absorbing misalignment of the internal rotating components, such as a crankshaft, of a combustion engine.